I think mathematically it's a very tricky spot and you're spot on. However, with no discredit to Craig, he never expects me to fold the river once I call the turn (since I should always b/3b backdoor draws or check them), and therefore he will never bluff the river. Of course, now that this hand took place, the dynamic changes; but, when Craig and I have played HU throughout our careers, I never make big folds on the river. So, he isn't gonna bluff me on the river in this
specific hand no matter what he says

.
Also Aaron this is why I bet the turn. Because I know exactly how to play against all actions on both the turn and river (and I think the value I get from betting the turn to either induce c/r or weaker calls is large). I'll check back the river if he checks it though.